Lubricated hook for sewing machines



May 26, 1942. w. J. PEETS ET AL LUBRIGATED HOOK FOR SEWING MACHINES 2Sheets-Sheet 1 Filed June 22, 1939 gwuma bo o wilbur (I Peeia .DaviidflGraesser and Witness Ieonard C. mar-sac F May 26, 1942- w. J. PETs l ITAL 2,284,474

LUBRICATED HOOK FOR SEWING MACHINES Filed June 22, 1939 v 2 sneaks-sheet2 will)? peeia avid race-ser- WWW: a Leonarda marsac Patented May 26,

LUBRICATED HOOKFOR S E'WEING MACHINES Wilbur J. Peets and David A.Graesscr, Elisabeth.

and LeonardC. Marsac, Cranford, N. .i., assignors to The SingerManufacturing @ompany, Elizabeth, N. 1., a corporation of New JerseyApplication June 22, 1939, Serial No. iifittdtii 10 Claims.

This invention relates to sewing machines and more particularly toimproved means for lubricating the raceway of a rotatable hook in whichthe stationary bobbin-case is journaled.

One of the objects of this invention is to provide improved means forsupplying oil to the raceway of a rotatable hook during the operation ofthe machine and to discontinue supplying the oil when the machine isidle.

Another object of this invention is to supply a larger quantity of oilto the hook raceway when the machine is operating at high speeds than issupplied when the machine is operating atlow speeds.

Still further objects of this invention are to provide improved meansfor shutting off the supply of oil to the hook raceway and to providemeans for returning oil, which may escape from the front bearing bushingof the hook-shaft, to the oil-reservoir.

A still further object of this invention is to provide a readilyremovable filter for filtering the oil before it is delivered to theraceway of the hook.

With the above and other objects in view, as will hereinafter appear,the invention comprises the devices, combinations and' arrangements ofparts hereinafter set forth and illustrated in the accompanying drawingsof a preferred embodiment of the invention, from which the severalfeatures of the invention and the advantages attained thereby will bereadily understood by those skilled in the art.

In the drawings:

Fig. 1 is a vertical sectional view taken through the bed of a sewingmachine embodying my invention, some of the mechanism below the bedbeing shown in elevation.

Fig. 2 isan end elevation of the bearing bushing for the hook-shaft, onan enlarged scale.

Fig. 3 is an enlarged side elevation of the hook, the hook-actuatingshaft, and a bearing bushing for the hook-shalt, the depending lug ofthe bed in which the bushing is fixed being shown in section.

Fig. 4 is a horizontal sectional view taken substantially along the line4-4 of Fig. 2.

Fig. 5 is an enlarged sectional view of the filtering cartridge and itsholding means.

In the embodiment of this invention selected for illustration l0represents the bed-plate of a machine formed with depending side and endwalls which rest upon the gasket of resilient material ll carried by theoil-pan l2. The bed of the sewing machine together with the oil-panjournaled in the bearing bushings 23, ll carried by the bed. Fixed tothe end of the shaft I1, is a rotary hook it which cooperates with theusual.

reciprocatory needle It) in the formation of lock stitches. For a moredetailed description of the sewing machine oil-pan and oil-pumpreference may be had to the copending application of R. Kaier for aSewing machine, Serial No. 152,707, filed July 9, 1937.

As more clearly shown in Fig. 4 the bearing bushing is formed with aconduit 22 which is connected with the centrifugal pump l3 by the tube23 so that when the machine is operating oil is supplied from thereservoir A by the centrifugal pump l3 through the tube 23 and to theconduit 22 under pressure. Conduit 22 communicates with an internalcircular groove 24 which is formed in the bushing and supplies oil tothe bearing surface between the bearing bushing 20 and the shaft H, theshaft l'l being provided with a spiral groove 25 which returns the oilto the reservoir. The bearing bushing is also formed with a conduit itwhich is tapped to receive a screw 21. The conduit 26 is arranged belowthe level of the hook-shaft M (Fig. 2) and connects the circular groove26 with a second circular groove 28 which is formed slightly eccentricrelative to the shaft ll so that its outer periphery will intersect theconduit 26 but will not intersect the conduit 22.

The shaft 5! is formed with a longitudinal arranged bore and a radialduct 3! which communicates with the circular groove 2% in the bearingbushing M. The end of the hook-shaft 'l'l, to which the hook Iii isfixed. is provided with a screw 32 which closes the open end of thelongitudinal bore in the shaft ll. Carried by the screw and extendinginto the bore is a tube 33 filled with fibrous material beheld togetherby a ordinary pipe cleaner and functions to hold the fibers separate andprevents them from being packed too tightly in the tube. This rib alsomaintains the filtering material in its predetermined form and permitsthe fibrous material to be readily and accurately inserted in the tube.

The screw 82 is formed with a radial duct 36 which leads. the oil, thatpasses through the filter 34, to a circular chamber 31 formed betweenthe screw 32 and the hook-shaft. The oil is led from the chamber 31through a radial duct 38 and circumferential groove 38' in the shaft.l'| to the conduits 39 formed in the body of the hook l8. Theseconduits 39 are disposed substantially 180 apart and the outer ends areconnected with the raceway 40 formed in the hokbody by the grooves 4|.Journaled in the raceway 40 in the hook-body is the bearing rib 42 ofthe usual stationary thread-case 43. It will be understood that thethread-case is formed with an ear 44 which cooperates with a thread-caserestraining finger fixed to a stationary part of the machine, for thepurpose of preventing the thread-case from turning with the rotary hook.

Due to the pressure created by the pump i3 some oil may leak from theend of the bearing bushing 20 adjacent the hub 45 of the hook It. Tolead any oil which may escape from this end of the bushing back to theoil-reservoir, the bore in the hub 45 of the hook |8fis flared outwardlyto form a conically' shaped bore 46, and when the machine is operatingthe oil is thrown by centrifugal force against the wall of the conicalbore 46 and due to its inclined surface climbs along the wall towardsthe larger diameter of the bore, and is finally' thrown oil. into thecircular groove 41 formed in the depending lug 20. Any oil which may bethrown off into the groove 41 is returned to the reservoir by theinclined conduit 48 (Fig. 3). a

The operating of the lubricating device is as follows: When the machineis operated the vertical shaft l4 through its operative connection withthe driven needle-bar shaft (not shown) actuates the impeller in thecentrifugal pump l3 thereby forcing oil from the reservoir A through thetube 23 and conduit 22 in the bushing 20 to the circular groove 24. Somof the oil supplied to the groove 24 is used to lubricate the bearingsurface between the hook-shaft l1 and the hearing bushing 20 and theremainder of the oil is conducted through the conduit 26, circulargroove 28, and radial duct-1| to the longitudinal bore 30 in the shaftIT. The oil which is under pressure in the longitudinal bore 30 passesthrough the fibrous material 3 in the removable filtering cartridge 33,through the radial duct 36 to the circular chamber 31, from whence it isconducted through the radial ducts 38 and circular groove 38 to theconduits 39 formed in the hook-body, the oil being conducted from theouter ends of the conduits 39 to the raceway 40 in the hookbody by thegrooves. 4|. It will be understood that centrifugal force holds the oilin these grooves 4| and the grooves are slightly inclined outwardlytowards the raceway 40.

From the foregoing it will be observed that the oil-reservoir is locatedbelow the shaft H and that oil is supplied to the raceway in the rotaryhook under pressure ,and only when the .machine is operating. It will beapparent that the pressure of oil supplied tov the longitudinal bore inthe shaft varies with the speed of the machine due to the fact that thecentrifugal pump I 3 is directly connected with the actuating mechanismof the machine. It is, therefore,

apparent that a greater amount of lubricant is stitched, it is sometimesdesirable to operate the machine without supplying lubricant to theraceway of the hook. The flow of oil may be stopped by turning the screw27 until it covers the duct or the screw 21 may be removed to stop theflow of oil to the hook-raceway, the oil is allowed to escape throughthe conduit 26 back to the reservoir. When'the screw is removed the oilpressure in the conduit 26 is reduced and, due to the centrifugal forcecreated by the radial duct 3| in the shaft I1, which is greater than thereduced pressure in the conduit 26, oil will not be forced into thelongitudinal bore 30 of the From the foregoing description it will beobvious that the elements employed and details of construction aresusceptible of material variations. The privilege is therefore reservedof resorting to all such legitimate changes therein as may be fairlyembodied within the spirit and scope of the appended claims.

Having thus set forth the nature of the invention what we claim hereinis:

1. In a sewing machine, a hook-actuating shaft formed with alongitudinal bore, a bearing bushing in which said shaft i journaled, aconduit formed in said bushing and arranged parallel to and at one sideof said shaft for conducting oil to the bearing surface of said shaftand a second conduitformed in said bushing and connected with said firstconduit for conducting oil to the bore in said shaft, a rotary hookformed with a raceway and fixed to one end of said shaft, said hookbeing provided with an oil conducting passage; for leading oil from thebore in said shaft to the raceway in said hook, an oil-reservoir locatedbelow said bushing, and means for supplying oil under pressure from saidoil-reservoir to the first mentioned conduit in said bushing.

2. In a sewing machine, a hook-actuating shaft formed with alongitudinal bore, a bearing bushing which said shaft is journaled, aconduit formed in said bushing for conducting oil to the bearing surfaceof said shaft and a second conduit formed in said bushing for conductingoil to the bore in said shaft, a rotary hook formed with a'raceway andfixed to one end of said shaft, said hook being provided with an oilconducting passage for leading oil from the bore in said shaft to theraceway in said hook. an oil-reservoir, means for supplying oil fromsaid oil-reservoir to the first mentioned conduit in said bushing, andmeans for closing said second conduit to prevent oil'from being suppliedto the bore in said shaft.

3. In a sewing machine having a rotary hook formed with a raceway and ashaft formed with a longitudinal bore, means for supplying oil throughthe bore in said shaft to the raceway in said hook, and a removablemetal tube filled with fibrous material extending into the bore of saidshaft for the purpose of filtering the oil supplied to the raceway inthe hook.

4. In a sewing machine having a rotary hook and a bobbin-carrier havingmeans-with said rotary hook, a shaft carrying said hook and formed witha longitudinal bore, an oil-reservoir, means for supplying oil frominterengaging said reservoir through said longitudinal bore to theinterengaging means and a screw carried by the end of said shaft, saidscrew carrying a self-contained filtering cartridge.

5. In a sewing machine, a rotating shaft, a bearing in which said shaftis journaled, a hook having a hub which surrounds said shaft andterminates adjacent said bearin said hub being formed with a conicallyshaped bore in the end adjacent said bearing, said conically shaped boreflaring outwardly toward the end of said hub adjacent said bearing andproviding a clearance space between said bore and shaft.

6. In a sewing machine, a rotating shaft, a bearing in which said shaftis journaled, an oilreservoir, means for supplying oil from saidreservoir to said bearing, a hook carried by said shaft and having a hubwhich surrounds said shaft and terminates adjacent said bearing, saidhub being formed with a conical bore for causing any oil which mayescape from said bearing tube thrown off the end of the hubadjacent-said bearing, and means for collecting any oil which may bethrown off and returning it to said reservoir.

7. In a sewing machine, a hook-actuating 0 parallel to said shaft, a'duct communicating with said conduit and leading to thebearing surfacebetween said shaft and said bushing, a sec- -are arranged parallel tothe shaft one of said conduits communicating with the bearing 0ndconduit connecting said' duct with the longi- Y tudinal bore in saidshaft, a rotary hook formed with a raceway and fixed to one end of thehook-actuating shaft, said hook being provided with an oil conductingpassage which communicates with the bore in said shaft and theraceway insaid hook, an oil-reservoir, means for supplying oil from said reservoirto the first mentioned conduit in said bushing and means for regulatingthe flow of oil'through said second conduit.

8. In a sewing machine, a hook-actuating shaft formed with alongitudinal bore, a rotary surface between the shaft and the bearingbushing and the other of said conduits being connected with the firstconduit to receive oil therefrom and conduct it to the bore in saidshaft, an oil-reservoir, and means for -supplying oil from thereservoir. to theflrst mentioned conduit in said bushing. is

9. In a sewing machine, a hook-actuating shaft formed with alongitudinal bore, a bearing in which said shaft is journaled, a conduitfor supplying lubricant to said bearing, a pump for controlled valvelocated in-said bearin for re8- ulating the flow of lubricant throughsaid means 'whereby the bearing for the shaft will be lubricated underpressure at all times and the flow of lubricant to the longitudinal borein the hookshaft is under the control of the operator.

10. In a sewing machine having a rotary hook and a bobbin-case iournaledin a raceway in said hook a shaft for supporting and'actuating saidhook, said shaft being formed with a longitudinal bore, an oilreservoir, means for supplying oil under pressure from said reservoir tosaid bore, and a readily insertable and removable selfcontainedfiltering cartridge comprising a rigid tube having a'flbrous materialcompressed therein and located in said bore.

WILBUR J. PEETS. DAVID A. GRAESSER. LEONARD 0. MAC.-

